But I will take you at your word. These Union soldiers were considered as "traitors" by your own words, therefore their burial was not one of honor nor respect, unless you are saying it was the custom of the south at that time to buried traitors with honor, unless you are saying they were buried as traitors but with respect.
The white officers were also thrown into the common grave with the black soldiers you have called "traitors", a classification you have now justified here for a second time. The white Massachusetts officers certainly owed no loyalty or allegience to the south by any stretch of anyone's imagination. Since they were thrown into the same graves with "traitors" they were definitely not given a burial of honor, even by your own admission, unless you are saying burying officers anonymously with men considered criminals is an honorable burial.
By your own words, these white Union officers were buried with the soldiers the burial party themselves dishonored as "traitors", and so they were therefore treated with equal dishonor.